摘 要:乳过氧化物酶是一种来自动物乳汁的过氧化物酶，它是一种血红素蛋白。牛奶中乳过氧化物酶的研究，可以为牛奶保质提供一些方法。本文主要是对加工后的牛奶中乳过氧化物酶活性和牛奶染菌进行研究,以在消费者饮用牛奶时提供一些建议。
本实验选择甘蒂牧场、金典、特仑苏、卫岗鲜牛奶、蒙牛奶粉和莫斯利安这几种不同加工工艺的牛奶作为样品。测定各牛奶样品中乳过氧化物酶的活性，并探索不同牛奶样品在常温和低温下开口放置后的染菌情况。观察细菌的生长情况并对其进行革兰氏染色，结果表明样品开口放置4h后，低温放置的牛奶样品的细菌生长数量比常温放置的少，并且牛奶样品的酸度值和pH均上升。特仑苏、甘蒂牧场和莫斯利安中滋生的细菌均为革兰氏阴性菌。金典中滋生的细菌有霉菌和革兰氏阴性菌。卫岗和蒙牛中滋生的细菌既有革兰氏阳性菌又有革兰氏阴性菌，且在LB培养基平板上均长出大量的革兰氏阴性杆菌。
该论文有图7幅，表5个，参考文献11篇。
关键词：乳过氧化物酶 牛奶 酶活 革兰氏染色
Determination of lactoperoxidase activity in milk and observation of its infection
Abstract:The lactoperoxidase is a peroxidase from animal milk, which is a hemoprotein. The study of lactoperoxidase in milk may provide some way for the milk to be bonded. This paper mainly studies the lactoperoxidase activity and milk-stained bacteria in processed milk to provide some advice when consumers drink milk.
In this experiment, we selected milk samples from different processing techniques such as Gandy Ranch, SATINE, Milk deluxe, Wei Gang fresh milk, Mengniu milk powder and Momchilovtsi. Measure the activity of lactoperoxidase in each milk sample and explore the condition of the bacteria in different milk samples at ambient temperature and low temperature. Observe the growth of bacteria and its Gram stain. The results showed that the number of bacteria in the milk samples was less than that at room temperature after the sample was placed for 4 hours, and the acidity and pH of the milk samples were both increased. The bacteria that breed in Milk deluxe, Gandi Ranch and Momchilovtsi are Gram-negative bacteria. The bacteria in SATINE are mold and gram-negative bacteria. Wei Gang and Mengniu breeding bacteria both Gram-positive bacteria and Gram-negative bacteria, and there are a large amount of gram-negative bacillus is grown on the LB medium plate.
Key Words: Lactoperoxidase Milk Enzyme activity Gram stain
目 录
摘 要 I
Abstract II
目 录 III
图清单 IV
表清单 IV
1 绪论 1
2材料与方法 2
2.1实验材料 2
2.2实验方法 4
3结果与分析 5
3.1 牛奶样品中乳过氧化物酶活性 5
3.2牛奶样品于常温、4℃开口放置后细菌滋生情况对比 6
4讨论 11
参考文献 12
致谢 13
图清单
图序号 图名称 页码
图2-1 牛奶样品 牛奶中乳过氧化物酶活性的测定及染菌观察:http://www.chuibin.com/shengwu/lunwen_206201.html